Supplying Power Efficiently - 1 vs 2 PSUs for 4x7970s

[Oreganobag]

I'm looking to set up a small farm of 4 - 8 GPUs for litecoin/scrypt alt-coin farming. Money isn't too much of an issue, but I'd still like to get some of your guys' thoughts on how I should go about powering the rigs.

If I can get 4 GPUs on one board (I know I could get 5-6, but I'm not sure if I could get PCIE risers here in Bangkok and importing computer parts is a bitsh with taxes and luxury fees), how would you go about powering them.

I would be overclocking them as much as possible to squeeze out every ounce of the rigs power that I can. I'm looking to squeeze the highest efficiency I can out of these things. With that in mind, would you go with 2 x 800ish W PSUs or would 1 x 1500W be enough? Would 1250 be enough?

I know 7950s would be cheaper to start up with, but the 70s might retain their value a bit better once the next gen of cards is released.

Thanks!

[Kaepora]

I'm looking to set up a small farm of 4 - 8 GPUs for litecoin/scrypt alt-coin farming. Money isn't too much of an issue, but I'd still like to get some of your guys' thoughts on how I should go about powering the rigs.

If I can get 4 GPUs on one board (I know I could get 5-6, but I'm not sure if I could get PCIE risers here in Bangkok and importing computer parts is a bitsh with taxes and luxury fees), how would you go about powering them.

I would be overclocking them as much as possible to squeeze out every ounce of the rigs power that I can. I'm looking to squeeze the highest efficiency I can out of these things. With that in mind, would you go with 2 x 800ish W PSUs or would 1 x 1500W be enough? Would 1250 be enough?

I know 7950s would be cheaper to start up with, but the 70s might retain their value a bit better once the next gen of cards is released.

Thanks!

One nice 1250W power supply is enough for 4 GPUs

[Oreganobag]

I'm looking to set up a small farm of 4 - 8 GPUs for litecoin/scrypt alt-coin farming. Money isn't too much of an issue, but I'd still like to get some of your guys' thoughts on how I should go about powering the rigs.

If I can get 4 GPUs on one board (I know I could get 5-6, but I'm not sure if I could get PCIE risers here in Bangkok and importing computer parts is a bitsh with taxes and luxury fees), how would you go about powering them.

I would be overclocking them as much as possible to squeeze out every ounce of the rigs power that I can. I'm looking to squeeze the highest efficiency I can out of these things. With that in mind, would you go with 2 x 800ish W PSUs or would 1 x 1500W be enough? Would 1250 be enough?

I know 7950s would be cheaper to start up with, but the 70s might retain their value a bit better once the next gen of cards is released.

Thanks!

One nice 1250W power supply is enough for 4 GPUs

Even with an overclock?

Cheers!

[Kaepora]

I'm looking to set up a small farm of 4 - 8 GPUs for litecoin/scrypt alt-coin farming. Money isn't too much of an issue, but I'd still like to get some of your guys' thoughts on how I should go about powering the rigs.

If I can get 4 GPUs on one board (I know I could get 5-6, but I'm not sure if I could get PCIE risers here in Bangkok and importing computer parts is a bitsh with taxes and luxury fees), how would you go about powering them.

I would be overclocking them as much as possible to squeeze out every ounce of the rigs power that I can. I'm looking to squeeze the highest efficiency I can out of these things. With that in mind, would you go with 2 x 800ish W PSUs or would 1 x 1500W be enough? Would 1250 be enough?

I know 7950s would be cheaper to start up with, but the 70s might retain their value a bit better once the next gen of cards is released.

Thanks!

One nice 1250W power supply is enough for 4 GPUs

Even with an overclock?

Cheers!

If you are going to be doing like +20% power limit or over-volting and massive overclocking with 4 cards they could go up to 300W each (250W x 1.20), if that is the case get a 1500W but remember that there is a point, at least with my cards where if I push them any further I get some more hashes but at the expense of more electricity. Also over-volting will create much more heat dont forget about cooling.

[Oreganobag]

I'm looking to set up a small farm of 4 - 8 GPUs for litecoin/scrypt alt-coin farming. Money isn't too much of an issue, but I'd still like to get some of your guys' thoughts on how I should go about powering the rigs.

If I can get 4 GPUs on one board (I know I could get 5-6, but I'm not sure if I could get PCIE risers here in Bangkok and importing computer parts is a bitsh with taxes and luxury fees), how would you go about powering them.

I would be overclocking them as much as possible to squeeze out every ounce of the rigs power that I can. I'm looking to squeeze the highest efficiency I can out of these things. With that in mind, would you go with 2 x 800ish W PSUs or would 1 x 1500W be enough? Would 1250 be enough?

I know 7950s would be cheaper to start up with, but the 70s might retain their value a bit better once the next gen of cards is released.

Thanks!

One nice 1250W power supply is enough for 4 GPUs

Even with an overclock?

Cheers!

If you are going to be doing like +20% power limit or over-volting and massive overclocking with 4 cards they could go up to 300W each (250W x 1.20), if that is the case get a 1500W but remember that there is a point, at least with my cards where if I push them any further I get some more hashes but at the expense of more electricity. Also over-volting will create much more heat dont forget about cooling.

Cooling isn't an issue. Dedicated room with aircon and fan blowing on them open-air.